Bioremediation - Asian Journal of Pharmacy and Life Science

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Asian Journal of Pharmacy and Life Science ISSN 2231 – 4423Vol. 2 (2), April-June,2012(usually indigenous microorganisms) capable of degrading target contaminants. In general, the rate and extent ofbiodegradation are greater in a bioreactor system than in situ or in solid-phase systems because the containedenvironment is more manageable and hence more controllable and predictable. Despite the advantages of reactorsystems, there are some disadvantages. The contaminated soil requires pre treatment (e.g., excavation) oralternatively the contaminant can be stripped from the soil via soil washingor physical extraction (e.g., vacuumextraction) before being placed in a bioreactor.Table 3. Developmental methods applied in bioremediation [10,11]Technique Examples Benefits Applications ReferencesIn Situ BiospargingMost efficient[12,6,1Non Invasive3]BioventingBioaugmentationEx situ Land farming (Solid-phasetreatment system)BioreactorsPrecipitationor FlocculationMicrofiltrationComposting(Anaerobic,converts solidorganic wastes into humus-likematerial)BiopilesSlurry reactorsAqueous reactorsNon-directed physico-chemicalcomplex -ation reactionbetween dissolved contamin -ants and charged cellularcomponents (deadBiomass)Microfiltration membranes areused at a constant pressureElectrodialysis Uses cation and anionexchange membrane pairsRelative passiveNaturally attenuated process, treatsoil and waterCost efficient ,Simple,Inexpensive ,self-heatingLow cost Rapid reactionrate, Inexpensive, self heatingCan be done on siteBiodegradative abilities ofindigenous microorganisms Presenceof metals and inorganic compoundsEnvironmental parametersBiodegradability of pollutantsChemical solubility GeologicalfactorsDistribution of pollutantsSurface application, aerobic process,application of organic materials tonatural soils followed by irrigationand tillingTo make plants healthier goodalternative to land filling orincinerating practical and convenient.Surface application, agricultural tomunicipal waste207 | P a g e Available online on www.ajpls.com Review Article[8,9]Rapid degradation kinetic Bioaugmentat Toxicity of [14]Optimized environmental amendmentsparametersEnhances mass transferToxic concentrations of contaminantsEffective use of inoculantsand surfactantCost-effective Removal of heavy Metals [15]Remove dissolved solids rapidlyWithstand high temperature andcan be reusedWaste water treatment; recovery andreuse of more than 90% of originalwaste waterRemoval of dissolved solidsefficiently--
Asian Journal of Pharmacy and Life Science ISSN 2231 – 4423Vol. 2 (2), April-June,2012Special Features of Bioremediation• It is a natural process , it takes a little time, as an acceptable waste treatment process for contaminatedmaterial such as soil. Microbes able to degrade the contaminant increase in numbers when the contaminant ispresent; when the contaminant is degraded,the biodegradative population declines. The residues for thetreatment are usually harmless productsort• Bioremediation also requires a very less effort and can often be carried out on site, often without causing amajor disruption of normal activities. This also eliminates the need to transport quantities of waste off site andthe potential threats to human health and the environment that can arise during transportation.• Bioremediation is also a cost effective process as it lost less than the other conventional methods that areused for clean-up of hazardous waste.• It also helps in complete destruction of the pollutants , many of the hazardous compounds can be transformedto harmless products ,this feature also eliminates the chance of future liability associated with treatment anddisposal of contaminated material.• It does not use any dangerous chemicals. The nutrients added to make microbes grow are fertilizerscommonly used on lawns and gardens. Because bioremediation changes the harmful chemicals into water andharmless gases, the harmful chemicals are completely destroyed..Limitations of Bioremediation :-• Bioremediation is limited to those compounds that are biodegradable. Not all compounds are susceptible to rapidand complete degradation.• There are some concerns that the products of biodegradation may be more persistent or toxic than the parentcompound. Biological processes are often highly specific. Important site factors required for success include thepresence of metabolically capable microbial populations, suitable environmental growth conditions, and appropriatelevels of nutrients and contaminants.• It is difficult to extrapolate from bench and pilot-scale studies to full-scale field operations.• Research is needed to develop and engineer bioremediation technologies that are appropriate for sites with complexmixtures of contaminants that are not evenly dispersed in the environment. Contaminants may be present as solids,liquids, and gases.• Bioremediation often takes longer than other treatment options, such as excavation and removalof soil or incineration.• Regulatory uncertainty remains regarding acceptable performance criteria for bioremediation.There is no accepted definition of “clean”, evaluating performance of bioremediation is difficult208 | P a g e Available online on www.ajpls.com Review Article
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Bioremediation - Asian Journal of Pharmacy and Life Science

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